SINGAPORE - Wednesday's (Nov 25) rail disruption along the
North-South Line, which affected tens of thousands of commuters
during the morning peak, is worrying on two counts.
First, it involved yet another electrical fire. Fires in a mass
transit system, no matter how small, can have catastrophic
consequences. And there has been one too many recently.
Earlier this year, a circuit-breaker fire shut down the Bukit
Panjang LRT system for a day. In 2013, a short-circuit fire broke
out near Newton, engulfing the station in smoke and disrupting
service for two hours in the morning peak.
In 2004, a fire broke out in the tunnel near Newton, apparently
also caused by a short circuit.
Wednesday's fire on the North-South Line was said to have been
ignited by a flashover at a tie-breaker (a kind of circuit breaker)
in Ang Mo Kio MRT station. The blaze was put out by the Singapore
Civil Defence Force at 5.50am.
A flashover is an unintended discharge of current, which can leap
across voids. It can happen when a system is stressed with a
higher-than-usual electrical load.
Was the system under a higher-than-usual load, with additional
trains and newer and heavier ones? SMRT would not comment.
There was a strong suspicion that a heavier-than-usual electrical
load had caused the Bukit Panjang LRT fire. On the other hand,
Wednesday's incident happened before service started for the day,
so load could not have been the likely cause.
According to the Land Transport Authority (LTA), disruptions caused
by power and trackside faults more than doubled between 2011 and
last year.
In 2011, they accounted for eight incidents or 2 per cent of all
disruptions. Last year, they were responsible for 16 incidents or 5
per cent of incidents.
The unprecedented networkwide breakdown on July 7 this year was
also caused by an electrical fault - although there was no
fire.
Why is the system experiencing such a surge in electrical faults?
If this electrical problem is not tackled, a tunnel fire might one
day happen with serious consequences.
The second worrying thing about Wednesday's breakdown was what the
LTA chief executive said in its aftermath.
Mr Chew Men Leong, talking to reporters at Ang Mo Kio station on
Wednesday morning, described the incident as a "localised" one.
Although Mr Chew was speaking off the cuff, the comment downplays
the gravity of the situation unnecessarily.
Rail breakdowns are rarely "localised", unless it is a glitch on
the Sentosa monorail.
A breakdown on an MRT line, which can account for one million trips
a day, impacts not just people in a particular stretch. It affects
commuters both upstream and downstream of the affected stretch. In
fact, it can reverberate across the entire rail network, as
transfers are disrupted and train platforms become overcrowded -
often in an instant.
It impacts bus commuters, taxi availability and road traffic as
affected commuters spill out of stations onto the streets in search
of transport alternatives.
A rail breakdown - especially during peak hours - easily impacts
tens of thousands of people. A country's productivity is affected
as a consequence, not to mention students who are late for
exams.
What Mr Chew said on Wednesday morning about SMRT being able to
recover from the situation quickly was spot on, though. City-bound
trains on the North-South Line were running at intervals as short
as one minute after the incident. This was possible because drivers
overrode the system and drove the trains manually.
This helped to clear the crowd quickly. Checks by The Straits Times
at Bishan interchange found that trains went from fully packed at
9.15am to having ample standing room by 9.30am.
Trains on the adjoining Circle Line were running at intervals of as
short as two minutes, even though the electronic notice board said
four. That helped to dissipate the crowd on the platform that was
filled continuously by people transferring from the North-South
Line.
In this instance, it is clear the operator managed its recovery
process well, and that mitigated the impact of the breakdown
somewhat.
The challenge is, of course, to prevent a repeat of such
breakdowns. Although the number of breakdowns can never be zero,
the rising incidence of electrical faults and fires forms a
worrying pattern that cannot be ignored.
ST
